Molly,
We teach and model the question stems in whole group and small group, making sure students understand, learn and are able to apply them in their own work. Once we feel students are able to give it a try, they will respond once a week using the question stem and their own reading. The time to write their answer may be done during any of the Daily 5 sessions, it could be during their read to self time as they reflect on a passage, and it could also be during their writing time. We don't adhere to any specific task, it is about what works for that student.
The MSD referred to the State of Washington Question Stems. Hope that is helpful!
Kind Regards!
Gail Boushey